There has been well known a metal blind nut comprising a hollow tubular portion, an internally threaded portion formed at one of the ends of the tubular portion and a flange formed at the other end of the tubular portion, wherein the tubular portion is adapted to be buckled or deformed by inserting the tubular portion into a hole of a workpiece so that the blind nut is fastened to the workpiece by the deformed portion and the flange (for example, Japanese Utility Model Laid-Open No. 59-146607). The blind nut can be handled from one side of a workpiece in its fastening operation, and thereby conveniently fastened to the workpiece such as a panel even if an operator cannot access to the rear side of the workpiece. A bolt can be screwed into the blind nut fastened to the workpiece. For example, a headed bolt can be screwed into the internally threaded portion to attach various members such as an ornamental member to the workpiece.
Japanese Patent Laid-Open No. 11-223207 discloses a blind nut type elastic fastener which is not a metal blind nut. This elastic fastener comprises a hollow tubular portion, an internally threaded portion provided at one of the ends of the tubular portion and a flange formed at the other end of the tubular portion. Further, the tubular portion and the flange are formed of an elastic material such as a chloroprene rubber. Thus, the elastic fastener has excellent characteristics in vibration resistance and water tightness as compared to the metal blind nut.
In the elastic fastener disclosed in Japanese Patent Laid-Open No. 11-223207, the tubular portion and the flange are formed of a chloroprene rubber, but the internally threaded portion is formed as a metal nut. Thus, the elastic fastener still is involved with a challenge to be improved in terms of weight reduction, and is not adequate to recycle because it mixedly includes metal and rubber. Further, an adhesive is essential to attach the internally threaded portion to the tubular potion because these portions are made of metal and rubber, respectively. In addition, the chloroprene rubber as a material of the tubular portion and flange leads to long forming time and low ozone resistance.
It is therefore an object of the present invention to provide an elastic fastener capable of achieving sufficient weight reduction, elimination of the need for adhesive, reduced forming time, and enhanced ozone and vibration resistances.